1. Field of the Invention
The present invention relates to an image communication apparatus capable of transmitting data via the Internet, and more specifically to an image communication apparatus for transmitting an image after obtaining capability of a destination terminal on the Internet, a server apparatus for providing capability of the destination terminal, and a capability exchanging method.
2. Description of the Related Art
In conventional facsimile apparatuses, a G3 facsimile apparatus, which carries out data communications using an analog network, and a G4 facsimile apparatus, which carries out data communications using a digital network such as ISDN, etc., are generally used. Such facsimile apparatuses using the analog network and the digital network (hereinafter referred to as “public switched telephone network (PSTN)” in a word) are hereinafter called G3/G4 FAX. On the other hand, an Internet facsimile apparatus (hereinafter referred to as “IFAX”), that receives and transmits data over an Internet protocol, has been developed in recent years. Particularly, standardization of an e-mail type IFAX, which receives and transmits image data using an e-mail transfer protocol, has been developed in IETF (Internet Engineering Task Force) and ITU (International Telecommunication Union).
The following will explain the case using SMTP (simple mail transfer protocol) and POP (Post Office Protocol) 3 as a mail transfer protocol in transmitting data by an e-mail type IFAX.
IFAX transmits a mail to a SMTP server. The SMTP server transfers the mail to a POP3 server to which a receiver belongs. The POP3 server stores the mail in a mail box of a destination.
Since data communications by IFAX is non-synchronously carried out, capability exchange cannot be executed between IFAX and a communication terminal on the receiver side. For this reason, IFAX is intended to surely carry out communications by executing communications using a minimum function of a transmitter (sender) and the destination (receiver). As described in a document RFC2305 “A Simple Mode of Facsimile Using Internet mail” (K. Toyoda et. al; March 1998) issued by IETF, the minimum function, which IFAX should possess, is defined as a “simple mode”.
More specifically, the communication protocol is SMTP, and corresponds to MIME and a minimum set of a TIFF file.
The minimum set is defined in the above RFC2305. In the TIFF file, there are five sets such as S, F, J, L, and M, depending on a facsimile mode and a profile supporting the TIF file. Among these sets, the lowest one is the profile S, that is, the minimum set.
More specifically, the following points can be defined.
The minimum set supports a monochrome image.                A compression format is a MH (Modified Huffman coding);        A CPU is an Intel system;        A width of paper is 1728 (corresponding to A4 size);        Resolution is 100 dpi or 200 dpi; and        A data list is LSB.        
However, in communications using the simple mode, only the minimum function can be used. For this reason, even if both a transmitter terminal and a destination terminal have the function more than the simple mode, communications is carried out using the minimum function.
To solve such a problem, there is considered a communication system in which capability information of a terminal to be used as a destination terminal is registered in a server in advance such that the transmitter terminals can obtain capability information of the destination terminals from the server. For example, in the Unexamined Japanese Patent Publication No. Hei 10-334007 (corresponding to U.S. patent application Ser. No. 09/084,938 filed on May 28, 1998), such a communication system is disclosed. According to IFAX described in the above publication, since capability information of the destination terminals can be obtained before transmission is started, communications suitable for the capability of the destination terminals can be carried out.
However, in the above publication, a system for registering capability of a self-apparatus to a server is disclosed, a way for registering capability of a communication apparatus other than the self-apparatus is not disclosed therein. In conventional, in order to register capability information of desired destination terminal to a server, the user must obtain capability information of the destination terminal by some method and register it to the server by the user. For this reason, this forces the user to perform extremely complicated operations.